There has been known such a storage apparatus as a RAID apparatus which stores therein volumes (: LUs), i.e., logical units of its memory area, and which has a replication function for making a copy of data between the volumes. Allowing such a storage apparatus to execute the copy requires that a definition be given concerning between which volume and which volume the copy should be executed, and that the storage apparatus be made to recognize this definition. Conventionally, in contrast thereto, the following technology has been known: If an instruction of the copy for a certain volume has been received, a volume is selected which becomes a partner between which and this volume the copy should be executed. Next, in the storage apparatus, the copy is executed between these pair-volumes that have become the pair (refer to, e.g., JP-A-2001-318833).